Resources and Reserves

  • Sylvester Okotie
  • Bibobra Ikporo


The heart of the oil and gas business is the amount of hydrocarbon reserves found initially in place, which implies that the value of the reserve estimation is a key driver for exploration and production companies to decide whether to develop or abandon a prospect/field based on their set criteria. There are several parties involved in the utilization of the hydrocarbon reserves and it includes the operating companies, regulatory bodies, banks, investors to mention a few for different reasons. Some of these reasons are: to obtain approvals from relevant ministries and other regulatory bodies, for investment in oil/gas sector, for exploration and development plan strategy and for facilities design. Other reasons include obtaining financing, evaluation of profit/interest, satisfying government regulations & taxation, etc. Furthermore, there are several uncertainties associated with hydrocarbon reserve estimation which are presented in the later part of this chapter, and when these uncertainties are not factored into the prospect evaluation, the result is a wrong estimation of the reserves. Accordingly, this chapter presents a detailed understanding of hydrocarbon resource and its classification, understanding of hydrocarbon reserve and its classification and a brief definition of reservoir characterization.


Reserves Resources Contingent resource Prospective resource Proved reserve Probable reserve Possible reserve Uncertainties Play concept Prospect 


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© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Sylvester Okotie
    • 1
  • Bibobra Ikporo
    • 2
  1. 1.Department of Petroleum EngineeringFederal University of Petroleum ResourcesEffurunNigeria
  2. 2.Department of Chemical & Petroleum EngineeringNiger Delta UniversityYenagoaNigeria

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